Introduction

Basically hot keys provide quick access to a feature of software application by pressing finite set of one or more keys. These keys will work even when the specific application is inactive or hidden. Normally implementing hot-keys feature for an application is a complex process. I want to make it simple and it is needed for one of my projects. After spending some time with MSDN, I created the Smart Hot key Handler in C#.NET. It will very useful for .NET based windows application developers; they can use it even they don't have any knowledge on Win32 application and libraries.

Using the Smart Hot Key Handler

Smart Hotkey handler.NET allows Windows applications to subscribe all registered hotkey events with minimum efforts. It supports to register all normal keys and function keys as hot key with or without key modifiers (Alt, Shift, Control and Windows).

Add the following line of code inside of the Dispose method to release the hot key handler.

//remove all keys
this.hotKey1.RemoveAllKeys();
//remove the specific hot key
this.hotKey1.RemoveKey("Shift+End"); //you can call this method
//wherever you want to remove a hotkey.
//It will release the hotkey handler from your application.

Now you run and test your application, you can get the following messages when you hit one or more keys on your keyboard.

Sample Outputs

In the same way, you can customize the hot key combination based on your requirements.

Conclusion

I hope this will reduce your development time on hot key implementation for your application. Currently Windows key modifier combination hot-keys are not working properly. If you have any workaround or solution, please share with me.

This is my first article, so I look forward to getting your feedback on grammatical and technical mistakes. It will really help me to improve myself and write more useful articles.

Comments and Discussions

This small guide will help you in using this nice little component in terms of adding keys. Having done some bit of work with this tool, there are many great functionalities that you can embed into your applications from a global perspective within Windows Forms applications. For example, you can be able to set a combination of keys like CTRL + F2 to call a particular function in your app... say, open a file if it's a Text Editor or show a MessageBox to your users. The only important thing is that you test to see if the keys do actually work because some applications usually provide to their users shortcut keys such as CTRL + N to, for example, create a new file or open a new TAB like in Google Chrome or Firefox, which becomes very difficult to be overridden because they are not from a global level but from an application level, so always be testing any key combinations that you've implemented once you've run your app. Global level means that you are able to set a combination of keys that will be executed even when your application is not the currently active one being used by your users, while Application level means that your application needs to be active in order to detect the combination of keys that you have set. A good example is whenever you press the Windows key or the Start key, the Start menu pops up (if on Windows 7 and earlier), or the Start Screen shows up (if on Windows 8 and later). This is a global level key detection mechanism. This is different as compared to Application level, where you application needs to be active in order for the particular set or combination of keys to be detected or handled. A nice example is when you use the Form KeyDown or KeyPress events. You can only perform the key combinations coded when your form is active, otherwise, the keys won't be detected at all. What now this tool comes in and does is that it is able to detect the Global level events while your application is running, and mind you, it does not need to be the currently active one. This is because it intercepts or taps into the messages sent from the Keyboard to any active application, even while in the Desktop, making it have a sort of pervasive or always active design in whatever application you're using at the moment. This is super convenient and easy especially for those times when e.g. you want your application to detect if a user has copied text to the clipboard or wants to access a particular feature from your application while using another application. That's what makes this small tool stand out and majorly because all you have to do is add the keys or remove them. All the complexities of handling the keyboard hooks has been abstracted from you. All you need to do is drop the keys as a String, like: "Control + F2" together with the checking event and the procedure/function or code to be called, and it's all done for you.

You will be able to refer any key on that page from SmartHotKey like this:In C#:

AddHotKey("LWin"); //for the WINDOWS key or commonly named START key

AddHotKey("Back"); //for the BACKSPACE key

AddHotKey("CapsLock"); //for the CAPS-LOCK key

AddHotKey("NumLock"); //for the NUM-LOCK key

AddHotKey("Scroll"); //for the SCROLL-LOCK key

AddHotKey("F1"); //for the F1 Function key

In VB.NET:

AddHotKey("LWin") 'for the WINDOWS key or commonly named START key

AddHotKey("Back") 'for the BACKSPACE key

AddHotKey("CapsLock") 'for the CAPS-LOCK key

AddHotKey("NumLock") 'for the NUM-LOCK key

AddHotKey("Scroll") 'for the SCROLL-LOCK key

AddHotKey("F1") 'for the F1 Function key

You can hook practically every key in your Keyboard with this tool. Even the Function keys can be handled as it is able to perform the very base-level hooking of keys in your keyboard and therefore intercepts all the messages coming from your Keyboard first-hand. However, this can bring about issues whenever you've hooked the typing keys like Q or S, with the tool from your application. This is because you will now not be able to type-in any more with that key as the message that the key sends to any active application that requires input, say a Text editor, the message that the key sends will now be blocked from handing to the input what a user is typing. There can however be a way this can be solved, especially using function arguments (or function returns) that will return the default Message to the active application while performing the routines that you've added to the keys. Currently, I'm trying to work on this issue then will post the feedback here for the fix made (both for VB.NET and C# users). To the developer, great work and much appreciation for this handy job!

Hope this helps you and many others trying to use and/or find out the power of this great little tool for .NET apps!

and the Windows default event-handlers seem to be overriding it. it didn't work.my keyboard only has 1 'windows' button, its on the left, and I've tried both "LWin+D" & "RWin+D" and neither of these worked.

You will be able to refer any key on that page from SmartHotKey like this:In C#:

AddHotKey("LWin"); //for the WINDOWS key or commonly named START key

AddHotKey("Back"); //for the BACKSPACE key

AddHotKey("CapsLock"); //for the CAPS-LOCK key

AddHotKey("NumLock"); //for the NUM-LOCK key

AddHotKey("Scroll"); //for the SCROLL-LOCK key

AddHotKey("F1"); //for the F1 Function key

In VB.NET:

AddHotKey("LWin") 'for the WINDOWS key or commonly named START key

AddHotKey("Back") 'for the BACKSPACE key

AddHotKey("CapsLock") 'for the CAPS-LOCK key

AddHotKey("NumLock") 'for the NUM-LOCK key

AddHotKey("Scroll") 'for the SCROLL-LOCK key

AddHotKey("F1") 'for the F1 Function key

You can hook practically (and I mean, PRACTICALLY...) every key in your Keyboard with this tool. Even the Function keys as it is able to perform the very base-level hooking of keys in your keyboard and therefore intercepts all the messages coming from your Keyboard first-hand. However, this can bring about issues whenever you've hooked the typing keys like Q or S, with the tool. This is because you will now not be able to type-in any more with that key as the message that the key sends to any active application that requires input, say a Text editor, the message that the key sends will now be blocked from handing to the input what a user is typing. There can however be a way this can be solved, especially using function arguments (or function returns) that will return the Message to the active application. Currently, I'm trying to work on this issue then will post the feedback here for the fix made (both for VB.NET and C# users). To the developer, great work and much appreciation for this handy job!

Hope this helps you and many others trying to use and/or find out the power of this great little tool for .NET apps!